Dual Active Site Engineering in Porous NiW Bimetallic Alloys for Enhanced Alkaline Hydrogen Evolution Reaction

Abstract Utilizing dual active sites in electrocatalysts creates a synergistic effect, enabling the independent optimization of H 2 O dissociation and intermediate adsorption/desorption, which in turn enhances the efficiency of the hydrogen evolution reaction (HER). Herein, a porous NiW bimetallic alloy electrocatalyst using a dynamic H 2 bubble template (DHBT) strategy is fabricated. This electrocatalyst capitalizes on the synergistic effect of dual active sites, achieving industrial‐level current densities of 500 and 1000 mA cm −2 for HER in 1.0 M KOH, with low overpotentials of 198 and 264 mV, respectively. It also demonstrates excellent stability over a 200 h test. Theoretical studies reveal that alloying Ni with W shifts the d‐band center ( ε d ) of the W 5d orbital downward, which enhances *OH intermediate desorption and promotes H 2 O adsorption and dissociation at the W site, leading to increased active site availability. Meanwhile, this shift provides more accessible H* intermediates, further enhancing H 2 production at the Ni 2 W 1 hollow site. When the porous NiW bimetallic alloy electrocatalyst is implemented in a solar‐driven water splitting system, it achieves a high solar‐to‐hydrogen (STH) conversion efficiency of 16.59%. This work underscores the effectiveness of dual active site electrocatalysts for sustainable H 2 production.